Farming/Logging implements for FLU419

While I get my FLU419 running, it is time to think about attachments that would turn the FLU419 into a tractor substitute. I am not trying to beat a real farm tractor costing an order of magnitude more than a surplus FLU but there is enough evidence (especially on the other side of the pond) that a Unimog can be very useful on a small farm.

In order to use standard farm implements, I plan to fabricate a 3-point hitch that attaches in lieu of the backhoe. Something similar to the Case MB4/94 hitch shown here. Most farmers in the mountains of Western North Carolina are using Cat 1 implements, so this thing does not need to be as beefy as shown.

I expect the soft springs of the FLU419 to create some issues when plowing with a frame-mounted hitch. As a remedy, I would like to replace the shocks with hydraulic cylinders and plumbing that replicates the damping action of traditional shock and also allows to rigidly lock the suspension. In the "street" mode, the fluid would go straight into the reservoir on compression of the cylinder and during extension of the cylinder trough an adjustable restriction. That's essentially how a shock absorber works. Shutting both ports of the cylinders would turn them into rigid bars connecting axle and frame.

Any implements that need PTO input will be powered by a hydraulic PTO motor driven by the FLU rear hydraulics. Going from mechanical PTO to hydraulics and back to mechanical is wasteful but it also offers quick control and reversal without needing a second clutch or a reversing PTO box.

Looking forward to your comments, opinions, and ideas.

For the implement attachment part of it, there's a fair amount of info over on Benz World. I tend to get lost with all the variations of Unimogs, so I never did understand what fits what model. Partially that's because I'm not a Unimog person, per se. When I bought my SEE I bought a backhoe and loader. They just happened to be attached to a Unimog.

I think that the cylinder for lowering and raising the backhoe could be used as the upper link in a 3-point, but the implements would obviously not work the same as with regular lift arms on the bottom. Either way, Cat 1 stuff is pretty weenie for the power and weight of a SEE, I think. You should look at Cat 2 instead.

A while back I did figure out how to make lock-outs with hydraulic cylinders - in theory. I'll require a reservoir, of course, but I think that it could work with just one valve. If the cylinder doesn't take offense to negative pressure, that is. It may be safer to use two valves per cylinder.
For replicating the damping of a shock, you can try restrictors. They're dirt cheap, even at Tractor Supply.

The FLU farm said:

For the implement attachment part of it, there's a fair amount of info over on Benz World. I tend to get lost with all the variations of Unimogs, so I never did understand what fits what model. Partially that's because I'm not a Unimog person, per se. When I bought my SEE I bought a backhoe and loader. They just happened to be attached to a Unimog.

I think that the cylinder for lowering and raising the backhoe could be used as the upper link in a 3-point, but the implements would obviously not work the same as with regular lift arms on the bottom. Either way, Cat 1 stuff is pretty weenie for the power and weight of a SEE, I think. You should look at Cat 2 instead.

A while back I did figure out how to make lock-outs with hydraulic cylinders - in theory. I'll require a reservoir, of course, but I think that it could work with just one valve. If the cylinder doesn't take offense to negative pressure, that is. It may be safer to use two valves per cylinder.
For replicating the damping of a shock, you can try restrictors. They're dirt cheap, even at Tractor Supply.

Click to expand...

Thanks for the suggestions. Can you get me the compressed and extended length of the OEM shocks from any parts you may have laying around?

Unfortunately I never did get that far in my quest so I have no measurements yet. Which means that I don't know what cylinder(s) would be suitable.
If you hadn't bought my parts SEE, I'd be in a better position for tearing one apart.

The FLU farm said:

I think that the cylinder for lowering and raising the backhoe could be used as the upper link in a 3-point, but the implements would obviously not work the same as with regular lift arms on the bottom. Either way, Cat 1 stuff is pretty weenie for the power and weight of a SEE, I think. You should look at Cat 2 instead.

Click to expand...

I will try to use the backhoe tilt cylinder to raise and lower the lift arms via a mechanical link and then have one manual adjuster for leveling the drawbar.

alpine44 said:

I will try to use the backhoe tilt cylinder to raise and lower the lift arms via a mechanical link and then have one manual adjuster for leveling the drawbar.

Click to expand...

I have one of the elusive MB4/94 3pts. Need to rebuild it.
My plan was to add a second set of quick connects tee'd into the loader valves at the back of the cab. Then the controls in the cab would run the 3pt.

I have looked at the hydraulic pto. At 26gpm and 3000psi, it would be something like 40hp. Likely less due to efficiency and because the system doesn't run at 3000psi.

alpine44 said:

I will try to use the backhoe tilt cylinder to raise and lower the lift arms via a mechanical link and then have one manual adjuster for leveling the drawbar.

Click to expand...

That does sound like a better solution. But as is, there might be a restrictor or regulator for that cylinder. It's painfully slow, I think.
Then again, a 3-point doesn't have to move all that fast, and your linkage can be made to speed the movement up.

Speedwoble said:

I have one of the elusive MB4/94 3pts. Need to rebuild it.
My plan was to add a second set of quick connects tee'd into the loader valves at the back of the cab. Then the controls in the cab would run the 3pt.

I have looked at the hydraulic pto. At 26gpm and 3000psi, it would be something like 40hp. Likely less due to efficiency and because the system doesn't run at 3000psi.

Click to expand...

As I recall, it's 2,800 psi. Enough to run my snowblower, but with very little to spare. Especially since I like to keep the rpm down.

Just a suggestion, but how about a three point hitch system that mounts in the bucket itself? This could be removed anytime, and the driver can see what is happening when driving in reverse. I am in the planning stages of building one, any thoughts as to pros and cons of this method?

thingamadigger said:

Just a suggestion, but how about a three point hitch system that mounts in the bucket itself? This could be removed anytime, and the driver can see what is happening when driving in reverse. I am in the planning stages of building one, any thoughts as to pros and cons of this method?

Click to expand...

I can't quite visualize what you have in mind. A front-mounted hitch?

alpine44 said:

I can't quite visualize what you have in mind. A front-mounted hitch?

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I think he means in the backhoe bucket. I have thought about this myself as I have the see and a ford tractor but would like to use the see for my 3 point.
You can buy a universal 3 point mount and fab the mounts to the bucket or directly to the backhoe mounts. Plumb the hydro from the remote tools attachments for a pto.


just a thought

thingamadigger said:

Just a suggestion, but how about a three point hitch system that mounts in the bucket itself? This could be removed anytime, and the driver can see what is happening when driving in reverse. I am in the planning stages of building one, any thoughts as to pros and cons of this method?

Click to expand...

While I've never used it on the SEE, I have an adapter from quick attach to 3-point. Of course, it requires a quick attach conversion on the SEE's loader in the first place.
With the tractors I've used it a few times to pull snow away with a box blade, and to move implements around with, which is probably what it's intended for.

A 3-point setup on the bucket could be used to run a rear blade backwards, making it a plow when turned 180 degrees, which most blades can do. Or spread dirt with a box blade in reverse.
I don't know how much power a hydraulic mower/brush hog uses, but that could be another useful setup (run off of the rear hydraulics).
There's a lot of 3-point stuff available, but since I have tractors I use those implements on them instead. Making a 3-point for the bucket is an interesting idea, and worth doing, I think. If I didn't have the tractors and only a SEE, I would.
Come to think of it, my first 3-point implement was a blade left by the prior owner of a property...so I built a tractor to use it.